Peri-implantitis is characterized by an inflammatory process around an osseo-integrated dental implant, which includes both soft tissue inflammation and progressive loss of supporting bone [Elemek E, Almas K. Peri-implantitis: etiology, diagnosis and treatment: an update. The New York state dental journal 2014; 80 (1):26-32]. The reported prevalence rate of peri-implantitis range from 5% to 47%, depending on the thresholds for probing depth and radiographic bone loss used for disease definition, and the composition of study populations [Mombelli A, Muller N, Cionca N. The epidemiology of peri-implantitis. Clinical oral implants research 2012; 23 Suppl 6:67-76.]. If peri-implantitis progresses, it may result in the loss of the implant.
Peri-implantitis is an oral biofilm related disease characterized by changes in the level of the crestal bone in conjunction with bleeding on probing (BoP) with or without concomitant deepening of peri-implant pockets [Lang N P, Berglundh T. Periimplant diseases: where are we now? Consensus of the Seventh European Workshop on Periodontology. Journal of clinical periodontology 2011; 38 Suppl 11:178-181, Lee A and Wang H L. “biofilm related to dental implants”. Implant Dentistry 2010; 19(5):387-91].
Currently available treatments of peri-implantitis focus on correcting technical defects by means of surgery and decontamination techniques and were found to have only a limited effect on the clinical signs of peri-implantitis. Non-surgical treatments including a mechanical treatment alone or combined with antiseptics or antibiotics can improve clinical parameters in the short term. Surgical procedures for treating peri-implantitis include access flap and debridement, surgical resection, regeneration with bone grafts, and guided bone regeneration (GBR). In short term follow-up these procedures yield an estimated 2 to 3 mm probing depth reduction, equivalent to 30% to 50% on the initial probing depth. A mean 2 mm radiographic bone fill is achieved with regenerative procedures [Heitz-Mayfield L J, Mombelli A. The therapy of peri-implantitis: a systematic review. The International journal of oral &maxillofacial implants 2014; 29 Suppl:325-345].
Regenerative periodontal therapy, using bone grafts, membranes and growth factors, aiming at regenerating a new attachment apparatus and reconstruct the periodontal unit to within previously existing normal physiologic limits, has been used for the treatment of periodontitis. Bone graft substitutes currently available in the market for dental use include ceramic based products (e.g Bio-Oss®) and degradable polymers containing antibacterial drug (e.g. Atridox® which releases doxycycline, Arestin® which releases minocycline, and Actisite® with tetracycline). Atridox, Arestin, and Actisite are indicated for periodontitis treatment, and are used off label in peri-implantitis. Andre Buchter et al. (British Journal of Oral and Maxillofacial Surgery (2004) 42, 454-456) presented a single case study of peri-implantitis treated with a combination of autogenous bone graft with Atridox®. However, Atridox® high burst and the short release period of the antibiotic drug, for no more than several days following the implantation, represent significant limit to their anti-bacterial effect. Furthermore, as indicated above, no satisfactory treatment to peri-implantitis is currently available.
International Publication No. WO 2010/007623 to one of the inventors of the present invention and others, the contents of which are incorporated herein by reference, discloses drug delivery compositions for controlled release of an active ingredient, comprising a lipid-based matrix with a biodegradable polymer. These drug delivery compositions enable to entrap a large variety of one or more biologically active molecules and to release them at a pre-programmed rate for periods ranging from several days to several months.
International Publication No. WO2014/020610 to the inventor of the present invention, the contents of which are incorporated herein by reference, discloses compositions, methods and medical devices for the treatment of open bone fractures comprising the step of applying to a bone void site a composition comprising a matrix which provides local prolonged release of at least one antibiotic agent.
It would therefore be desirable to provide an improved method for the treatment of peri-implantitits which promotes the healing process of the infected mucosal, while enhancing peri-implant bone formation, improve implant survival rates and enhance the oral health-related quality of life.